A 3rd Generation Partnership Project (3GPP) Evolved Packet System (EPS) consists of an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), a Mobility Management Entity (MME), a Serving Gateway (S-GW), a Packet Data Network Gateway (P-GW), a Home Subscriber Server (HSS), a Policy and Charging Rules Function (PCRF) entity and other supporting nodes.
The MME is responsible for mobility management, the processing of the signaling of a non-access layer, the management of user mobility management context and other related work of a control plane; the S-GW, which is an access gateway device connected with an E-UTRAN, forwards data between the E-UTRAN and the P-GW and caches paging-waiting data; the P-GW, which is a border gateway of an EPS and a Packet Data Network (PDN), is responsible for the access of the PDN, the data forwarding between the EPS and the PDN, and other functions; the PCRF, which is a policy and charging rules function entity, is connected with an operator Internet Protocol (IP) service network via a Receiving Interface (Rx) to acquire service information, besides, the PCRF is also connected with a gateway device in a network via a Gx/Gxa/Gxc interface to take charge of initiating the establishment of an IP bearer, guaranteeing the Quality of Service (QoS) of service data, and controlling charging.
The EPS supports the intercommunication with a non-3GPP access network and achieves the intercommunication with the non-3GPP access network by means of an S2a/S2b/S2c interface. The non-3GPP access network includes a trusted non-3GPP access network and an untrusted non-3GPP access network. The IP access of the trusted non-3GPP network can be directly connected with the P-GW via an S2a interface while the IP access of the untrusted non-3GPP network is connected with the P-GW via an Evolved Packet Data Gateway (ePDG); and the interface between the ePDG and the P-GW is an S2b interface.
Proxy Mobile IPv6 (PMIPv6) is a network-based mobility IP management protocol according to which no mobile device is needed for any mobility management, a network is responsible for the mobility management of a user equipment, and the mobile device is unaware of the effect of a layer-3 connection brought by a movement. For a Mobile Node (MN), no matter wherever it moves, the MN considers itself on its Home Link. A PMIPv6-based 3GPP network architecture includes the following two key nodes:                a Local Mobility Anchor (LMA), which is a Home Agent of an MN, a topological anchor of a home address of the MN, and a binding router managing the MN, provides an LMA function at a P-GW in a 3GPP network and is responsible of the data forwarding between the MN and a Packet Data Network; and        a Mobile Access Gateway (MAG), which shields a network layer change brought by a mobile handover and completes a binding update operation on behalf of the MN; in a 3GPP network architecture, the MAG functions is provided by a corresponding network element S-GW, a trusted non-3GPP IP access network and an ePDG.        
Proxy mobility management is implemented between the LMA and the MAG via the Proxy Binding Update (PBU) message and the Proxy Binding Acknowledgement (PBA) message. The PBU message sent to the LMA by the MAG and the PBA message sent to the MAG by the LMA are present in the form of a message pair. The MAG sends a binding association between the home address of a user equipment MN and the proxy address of the MAG itself to the LMA via the PBU message, and the LMA stores the binding association so as to forward an uplink message and a downlink message of the MN through a correct route. The PBU message which is mainly for binding update, binding lifetime update and binding deletion is acknowledged by sending the PBA message from a corresponding LMA to the MAG.
As stated above, PMIPv6 is applicable to a plurality of network deployment scenarios of network-based mobility management protocols, for example, a Wireless Local Area Network (WLAN) architecture. More and more network architectures require an LMA to be capable of providing stream transmission distinguishing different services and policies according to different access networks connected. For instance, in a 3GPP mobile network system, a Policy and Charging Control (PCC) Framework and an Access Network Discovery and Selection Function (ANDSF) need to decide and provide policy rules based on access network information, for example, providing services of different transmission qualities for a roaming user and a non-roaming user, or providing different policy services according to different Service Set Identifiers (SSID) in a WLAN access scenario. In the current PMIPv6, an MAG can provide the following access network (location) information for an LMA:
Network-Identifier (SSID or PLMN information of a roaming destination, PLMN ID);
Access-Point-Name (the MAC address of an AP);
Operator-Identifier (information of AP operator); and
Geo-Location (the GPS information of a user).
As network technologies develop and more services are needed, terminal devices in a home network become more diversified and more intelligent. As a centralized intelligent interface, a Residential Gateway (RG) connects a home network with an external network to provide the connection, the general control and the coordination for the home network. At present, the International Standardization Organization Broadband Forum (BBF) is standardizing the authentication of home gateways and residual terminal devices, the scenarios involved include the authentication of the access of a residual terminal device from a BBF network via an RG. In this scenario, as shown in FIG. 1 which is a schematic diagram illustrating an architecture in which a terminal device is connected to an EPC via a BBF fixed network, a Circuit ID can serve as the location information of an access network, and here, the Circuit ID may be any one of the following items or any combination thereof:                a Router interface number, a Switching Hub port number, a Remote Access Server port number, a Frame Relay Data Link connection identifier, an Asynchronous Transfer Mode (ATM) virtual circuit number, and a Cable Data virtual circuit number.        
For instance, if in the architecture shown in FIG. 1, the line from the RG to the Access Network (AN) is an ATM/Digital Subscriber Line (DSL), then a user connected with a network through the RG can be identified by atm slot/port:vpi.vci, for example, atm 3/0:100.33 (slot=3, port=0, vpi=100, vci=33), in which slot is a slot number, port is a port number, vpi is a virtual path identifier, and vci is a virtual channel identifier.
It can be known that a Circuit ID is also information identifying the location of a network where a user is located. However, an MAG is unsupportive to the notification of a Circuit ID to an LMA in existing PMIPv6 architecture, and a General Data Transfer Platform (GTP) peer is also unsupportive to the notification of a Circuit ID to a correspondent GTP peer in a GTP architecture, thus making it inconvenient in practice.